A network in recent years such as a mobile phone system and a wireless LAN service is configured by many network providers, and each provider executes access or connection authentication with respect to access or connection to each own network. In this access authentication, a network identifies each user by a subscriber ID. This subscriber ID is stored in a terminal main body and an IC card accessible to a terminal, or the like.
An example of a conventional system is disclosed in Japanese Laid-Open Patent Application JP2004-072631A. As shown in FIG. 1, this conventional authentication system includes a mobile terminal 1, a base station 2 (referred to as BS 2 hereinafter), an authentication authorization accounting server 3 (referred to as AAA server 3 hereinafter), an access point 4 (referred to as AP 4 hereinafter), a network A 5 (e.g. mobile communication network), and a network B 6 (e.g. wireless LAN network).
The conventional authentication system including this configuration is operated as follows. The BS 2 is connected to the network A 5, and the AP 4 is connected to the network B 6. The AAA server 3 is commonly connected to the network A 5 and the network B 6. The mobile terminal 1 includes a first communication means (e.g. wireless LAN interface) configured to communicate with the AP 4 of the network B 6, and a second communication means (e.g. mobile network interface) configured to communicate with the BS 2 of the network A 5. The mobile terminal 1 includes a means configured to connect to a radio communication channel ensured with high security between the mobile terminal 1 the BS 2 and to transmit data for authentication by using the second communication means when communicating with the network B 6. The AAA server 3 determines whether or not the mobile terminal 1 is allowed to access the AP 4 on the basis of received data for authentication, and notifies the AP 4 of the result.
In access to different communication systems, it is required in the conventional technique to have two different subscriber IDs or a subscriber ID common to each communication system. Furthermore, this subscriber ID needs to be stored in a terminal which is desired to be connected to a communication system, or an IC card which stores a subscriber ID needs to be connected to the terminal and used. Therefore, a terminal which can be used by the user is limited to a terminal which stores the subscriber ID or a terminal connected by the IC card, so that a terminal which can be used by the user is limited.
Conventional techniques will be indicated below, which are related to a technique of a terminal device to access a communication system which requires authentication.
Japanese Laid-Open Patent Application JP2000-197114A discloses a management method of a mobile phone terminal to allow utilization of a communication system by simply switching a subscriber identification device which stores user information in the mobile phone terminal.
Japanese Laid-Open Patent Application JP2002-262360A discloses a technique to send and register a phone number and registered ID data to a mobile phone network by using a mobile phone which is capable of storing registered user ID data and personal data for each user, so as to respond to various subsequent requests with respect to a mobile phone which was authenticated by comparing with registered data.
Japanese Laid-open Patent Application JP2002-288139A discloses a technique in which an authentication server inputs a user ID and a password by proxy when a mobile phone logs in a web server, in a system of performing authentication to log in a website by interposing an authentication server between a mobile phone and a web server.
Japanese Laid-Open Patent Application JP2003-186848A discloses a technique to notify a mobile terminal of an ID and password when an authenticated user registers image data in a distribution server, in which a user connects the mobile terminal to a PC and notifies an data management server of an ID and password stored in the mobile terminal, so that a desired image can be obtained.
Japanese Laid-Open Patent Application JP-A-Heisei, 11-178057 discloses a wireless telephone device to allow communication by sharing a common identifier in wireless base station, and simply registering a slave device in a single wireless base station while being synchronized with the remaining wireless stations.
Moreover, Japanese Laid-Open Patent Application JP-A-Heisei, 8-140141 discloses a technique to deal with a plurality of mobile terminals as a single group, in which an operation by a user of a mobile terminal allows access to a call generated by another mobile terminal within the group, so that a proxy response or the like can be achieved.